The best sense of smell on Earth belongs to the largest land mammal, the African elephant, according to researchers at the University of Tokyo.

Their new study found that African elephant have 2,000 genes dedicated to recognizing odors - twice as many olfactory genes as dogs have, five times as many as humans and many more than 11 species of mammals considered to have a keen sense of smell.

The researchers wrote they could not determine a reason for the large number of elephant genes related to detecting odors, but they noted the animals' phenomenal sense of smell is crucial to their survival - allowing them to sniff out and defferentiate food, predator and mates.

Yoshihito Niimura, author of the study published in Genome Research, said, "The functions of these genes are not well known, but they are likely important for the living environment of African elephants.”

Niimura said future research will deepen scientists' “understanding of the sense of smell in humans,” by comparing the gene patterns in African elephants and primates.